1. Field of the Invention
The present invention relates to a mounting technique for a semiconductor device, and particularly relates to a semiconductor device, a method for manufacturing the same, and a flexible substrate for mounting a semiconductor.
2. Description of Related Art
For information devices such as large-sized computers, personal computers, and portable devices, the performance of these devices has been improved and the sizes of these devices have been reduced year by year. Thus, while the size of semiconductor elements mounted in these devices has been increased, the area of a mounting substrate on which the semiconductor elements are mounted has been decreased. Consequently, markets strongly demand that a large number of semiconductor elements be mounted in a limited substrate area. Thus, techniques for mounting and stacking a plurality of semiconductor elements have been developed as methods for meeting the above-described demand.
One of the techniques for mounting and stacking semiconductor elements uses one semiconductor element, a wiring member, and the like to form a first semiconductor package, and then a plurality of the first semiconductor packages are stacked so as to manufacture a second semiconductor package in which a plurality of semiconductor devices are stacked. Stacking techniques based on this form are disclosed in JP-A-2002-176135, JP-A-H8-236694, and JP-A-2000-286380.
In connection with the above-described techniques, JP-A-2006-278863 discloses a technique of using one semiconductor element, a bending-deformable flexible substrate, and the like to form a first semiconductor package, and then flexible substrates of a plurality of semiconductor packages are bent and joined to one substrate so as to manufacture a second semiconductor package. In addition to the above-described methods, as a technique of stacking semiconductor elements, a technique of stacking a plurality of semiconductor elements to manufacture one semiconductor package has been developed. Techniques based on this form are disclosed in U.S. Pat. No. 6,141,245 and JP-A-S59-222954.